Thyroid imaging reporting and data system score combined with Bethesda system for malignancy risk stratification in thyroid nodules with indeterminate results on cytology

Diagnostic performance of ultrasound risk stratification systems on thyroid nodules cytologically classified as indeterminate: a systematic review and meta-analysis

PURPOSE

Ultrasound (US) risk stratification systems (RSSs) are increasingly being utilized for the optimal management of thyroid nodules, including those with indeterminate cytology. The goal of this study was to evaluate the category-based diagnostic performance of US RSSs in identifying malignancy in indeterminate nodules.

METHODS

This systematic review and meta-analysis was registered on PROSPERO (CRD42021266195). PubMed, EMBASE, and Web of Science were searched through December 1, 2022. Original articles reporting data on the performance of US RSSs for indeterminate nodules were included. The numbers of nodules classified as true negative, true positive, false negative, and false positive were extracted.

RESULTS

Thirty-three studies evaluating 7,225 indeterminate thyroid nodules were included. The diagnostic accuracy was quantitatively synthesized using a Bayesian bivariate model based on the integrated nested Laplace approximation in R. For the intermediate- to high-risk category, the sensitivity levels of the American College of Radiology, the American Thyroid Association, the European Thyroid Association, the Korean Thyroid Association/Korean Society of Thyroid Radiology, and Kwak et al. were found to be 0.80, 0.72, 0.76, 0.96, and 0.97, respectively. The corresponding specificity measurements were 0.36, 0.50, 0.49, 0.28, and 0.17. Furthermore, for the high-risk category, the sensitivity values were 0.40, 0.46, 0.55, 0.47, and 0.10, while the specificity levels were 0.91, 0.90, 0.71, 0.91, and 0.99, respectively.

CONCLUSION

The overall diagnostic performance of the US RSSs was moderate in the differentiation of indeterminate nodules.

Diagnostic efficacy of a combination of the Chinese thyroid imaging reporting and data system and shear wave elastography in detecting category 4a and 4b thyroid nodules

Objectives

Differential diagnosis of benign and malignant thyroid imaging reporting and data system (TIRADS) category 4a and 4b nodules can be difficult using conventional ultrasonography (US). The objective of this study was to evaluate the diagnostic efficacy of a combination of the Chinese-TIRADS (C-TIRADS) and shear wave elastography (SWE) in detecting malignant nodules among category 4a and 4b thyroid nodules.

Methods

Among 409 thyroid nodules in 332 patients that we included in this study, 106 thyroid nodules were diagnosed as category 4a and 4b using C-TIRADS. We used SWE to measure the maximum Young's modulus (Emax) values of category 4a and 4b thyroid nodules. We calculated the diagnostic efficacy of only the C-TIRADS, only SWE, and a combination of C-TIRADS with SWE, and compared these, while taking the pathology results as the gold standard.

Results

The area under the ROC curve (AUC), sensitivity, and accuracy values of the combination of C-TIRADS and SWE (0.870, 83.3%, and 84.0%, respectively) were all higher when compared with the values of only the C-TIRADS (0.785, 68.5%, and 78.3%, respectively) or only SWE (0.775, 68.5%, and 77.4%, respectively) in the diagnosis of category 4a and 4b thyroid nodules.

Conclusion

In this study, we found that the combination of C-TIRADS and SWE significantly improved the diagnostic efficacy in detecting malignant nodules among category 4a and 4b thyroid nodules, and this could provide a reference for further use of this combination by clinicians for diagnosis and treatment.

An attempt to reduce unnecessary surgical procedures... Can ultrasound characteristics help in differentiating adenoma vs carcinoma in follicular thyroid neoplasms?

INTRODUCTION AND OBJECTIVES

Thyroid nodules frequently require ultrasound and Fine Needle Aspiration Cytology (FNAC) evaluation. However, FNA cytology does not allow differentiation between follicular adenoma and carcinoma on Bethesda type IV lesions. This situation leads to many unnecessary surgical procedures because it is not possible to assure the benignity of the lesions, even when most of the specimens correspond to adenomas or even other benign lesions. The objective is this study is to establish if there are any US characteristics that would help us to predict the risk of malignancy of nodules with a pathological diagnosis of follicular neoplasm in order to achieve a more conservative management for non-suspicious nodules.

MATERIAL AND METHODS

We studied 61 nodules in 61 patients (51 women and 10 men) that underwent thyroid surgery and had histopathological results of either follicular adenoma or carcinoma. Different US characteristics of the nodules were analysed (composition, echogenicity, margin, calcification status, the presence of halo and overall observer suspicion of malignancy) and were correlated with the histopathological analysis.

RESULTS

We have found a statistically significant association between the presence of calcifications, ill-defined borders and overall observer suspicion or impression (defined by well-known suspicious for malignancy ultrasonographic features, such as calcification, poorly defined margin, and a markedly hypoechoic solid nodule; and benign ultrasonographic features, such as predominantly cystic echogenic composition and the presence of a perinodular hypoechogenic halo) with follicular carcinoma. However all those features have shown low sensitivities in the present study (30%, 30% and 50%, respectively). On the other hand, the absence of halo sign has shown a sensitivity of 100% and a negative predictive value (NPV) of 100% in our study.

CONCLUSIONS

The presence of calcifications, ill-defined borders and the overall impression or suspicion of malignancy associate with a higher risk for follicular carcinoma in Bethesda type IV thyroid nodules but their absence do not allow to predict benignity in these nodules. Inversely, when a halo sign lesion is observed, benign follicular neoplasm should be considered.

Ultrasound-based computer-aided diagnosis for cytologically indeterminate thyroid nodules with different radiologists

PURPOSE

To evaluate a computer-aided diagnosis (CAD) technique in predicting malignancy for cytologically indeterminate thyroid nodules (TNs) as compared with different experienced radiologists.

METHOD

436 patients with 436 cytologically indeterminate TNs on fine-needle aspiration cytology (FNAC) were included and all were confirmed by surgical pathology. They were retrospectively analyzed with respect to ultrasound (US) characteristics using a commercially available CAD system (AmCAD-UT; AmCad BioMed, Taiwan, China) and reviewed by one junior and one senior radiologists.The CAD system and different experienced radiologists stratified the risk of malignancy using ACR TI-RADS category. The diagnostic performance by different experienced radiologists independently and after consulting the CAD (different experienced radiologists + CAD) and by the CAD alone were compared.

RESULTS

The different experienced radiologists showed significantly higher specificities than the CAD system alone. The combination of radiologist and CAD system showed improved diagnostic performance with an AUC (Area under the curve) of 0.740 in the senior radiologist and 0.677 in the junior radiologist, as compared with CAD (AUC: 0.585) alone (all P < 0.05). The combination of senior radiologist and CAD system had the highest diagnostic performance (AUC: 0.740) and specificity (68.9%) compared to the others (all P < 0.05).

CONCLUSION

The CAD system may play the potential role as a decision-making assistant alongside radiologists for differential diagnosis of TNs with indeterminate cytology.

Approach to FNA of Thyroid Gland Cysts

Fine needle aspiration is a well-known procedure for the diagnosis and management of thyroid lesions, representing the first diagnostic tool for the definition of their nature. In clinical practice, a thyroid nodule can be classified as solid, cystic, and partially cystic based on its internal components. Different thyroid imaging reporting systems and cytologic diagnostic systems have focused their attention on solid nodules, which are more frequently linked with a malignant outcome. In fact, numerous papers demonstrated that nodules with microcalcifications, a taller-than-wide shape, hypoechogeneity, and irregular margins, are more likely to be malignant on histology. Nevertheless, according to the literature, the risk of malignancy in a partially cystic thyroid nodule ranges between 3.3 and 17-5%, including, for instance, the possible diagnosis of a cystic papillary thyroid carcinoma and other malignant entities. Therefore, in the current review article, we are going to discuss the approach to thyroid cystic lesions on fine needle aspiration cytology.

Optimization of the Management of Category III Thyroid Nodules Using Repeat FNA and TIRADS

The aim of the study was to examine the benefits of the joint use of repeat FNA (rFNA) and EU-TIRADS in category III nodules in relation to the kind of atypia: nuclear vs. architectural (denoted by AUS and FLUS respectively). The study included 127 AUS and 1739 FLUS nodules with a known category of EU-TIRADS. Repeat FNA was performed in 82 AUS and 934 FLUS nodules of which 57 and 515 were excised, respectively. AUS nodules had higher malignancy risk than FLUS nodules. EU-TIRADS showed higher accuracy for AUS nodules, the opposite to rFNA, that had higher accuracy for FLUS nodules. The combined criterion for AUS nodules (at least rFNA-V or EU-TIRADS-4) maximized sensitivity (92.3%) with acceptable specificity (70.0%); OR: 28.0. In the case of FLUS nodules, the combined criterion (rFNA-V or EU-TIRADS-5) maximized specificity (95.2%) with 57.7% sensitivity and a low percentage (13.9%) of positive nodules, OR: 27.0. In both types of nodules, the low risk category in EU-TIRADS and benign result of rFNA excluded cancer. Concluding, category III nodules with and without nuclear atypia differ in their risk of malignancy and, consequently, diagnostic criteria adopted for the evaluation of these nodules with rFNA and EU-TIRADS should be specific to AUS and FLUS nodules.

2021 Korean Thyroid Imaging Reporting and Data System and Imaging-Based Management of Thyroid Nodules: Korean Society of Thyroid Radiology Consensus Statement and Recommendations

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Comparison of Korean vs. American Thyroid Imaging Reporting and Data System in Malignancy Risk Assessment of Indeterminate Thyroid Nodules

BACKGROUND

The management of cytologically indeterminate thyroid nodules is challenging for clinicians. This study aimed to compare the diagnostic performance of the Korean Thyroid Imaging Reporting and Data Systems (K-TIRADS) with that of the American College of Radiology (ACR)-TIRADS for predicting the malignancy risk of indeterminate thyroid nodules.

METHODS

Thyroid nodules diagnosed by fine-needle aspiration (FNA) followed by surgery or core needle biopsy at a single referral hospital were enrolled.

RESULTS

Among 200 thyroid nodules, 78 (39.0%) nodules were classified as indeterminate by FNA (Bethesda category III, IV, and V), and 114 (57.0%) nodules were finally diagnosed as malignancy by surgery or core needle biopsy. The area under the curve (AUC) was higher for FNA than for either TIRADS system in all nodules, while all three methods showed similar AUCs for indeterminate nodules. However, for Bethesda category III nodules, applying K-TIRADS 5 significantly increased the risk of malignancy compared to a cytological examination alone (50.0% vs. 26.5%, P=0.028), whereas applying ACR-TIRADS did not lead to a change.

CONCLUSION

K-TIRADS and ACR-TIRADS showed similar diagnostic performance in assessing indeterminate thyroid nodules, and K-TIRADS had beneficial effects for malignancy prediction in Bethesda category III nodules.

Ultrasonography and Fine-Needle Aspiration in Indeterminate Thyroid Nodules: A Systematic Review of Diagnostic Test Accuracy

OBJECTIVES/HYPOTHESIS

Sonographic risk criteria may assist in further prognostication of indeterminate thyroid nodules (ITNs). Our aim was to determine whether sonographic criteria could further delineate the post-test probability of malignancy in ITNs.

STUDY DESIGN

Meta-analysis of diagnostic test accuracy.

METHODS

A systematic review of Web of Science, MEDLINE, EMBASE, and CINAHL was performed from inception to April 15, 2021. Eligible studies included those which reported ultrasonographic evaluations with the American Thyroid Association (ATA) or the Thyroid Imaging Reporting and Data System (TIRADS) in adult patients with ITNs. ATA or TIRADS were scored as low (negative) or high (positive) malignancy risk using a previously validated binary classification. Primary outcomes included pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratio for all sonographic criteria. Studies were appraised using Quality Assessment of Diagnostic Accuracy Studies and the data were pooled using bivariate random-effects models.

RESULTS

Seventeen studies were included in the analysis. For Bethesda III, ATA had a specificity (0.90, 95% confidence interval (CI): 0.74-0.94), but a sensitivity of 0.52 (95% CI: 0.25-0.77). Conversely, K-TIRADS had the highest sensitivity (0.78, 95% CI: 0.62-0.89) with a specificity of 0.53 (95% CI: 0.31-0.74). Furthermore, American College of Radiology and EU TIRADS had specificities of 0.60 (95% CI: 0.36-0.80) and 0.81 (95% CI: 0.73-0.87) with sensitivities of 0.70 (95% CI: 0.37-0.90) and 0.38 (95% CI: 0.20-0.60), respectively. There were few studies with Bethesda IV nodules.

CONCLUSIONS

Though dependent on malignancy rates, Bethesda III nodules with low-suspicion TIRADS features may benefit from clinical observation, whereas nodules with high-suspicion ATA features may require molecular testing and/or surgery.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

Analysis of Clinical-Radiological-Pathological Factors in FN/SFN Bethesda Category Thyroid Nodules, Contribution of FNAB Repeat, Single Center Experience

Objectives:

Follicular neoplasm/suspected follicular neoplasm (FN/FNS) Bethesda Category (BC)-4 group cases are known as the gray zone. Nodules diagnosed in cytology are excised. However, very few of these nodules are malignant. Our aim is to investigate the usability of clinical-radiological-pathological parameters to reduce unnecessary surgery. In addition, we questioned the benefit of repeating fine-needle aspiration biopsy (rFNAB) in these nodules, which is not recommended, but performed for clinical or patient-related reasons.

Methods:

The files of all thyroid FNAB patients conducted in our institution between January 2014 and September 2020 were scanned in the database. In our study, 185 (5.1%) nodules with cytology results of which were classified as FN/FNS were identified among 3624 nodules that were applied FNAB during this period. Twenty-eight patients were excluded from the study group. 157 nodules belonging to 157 patients between the ages of 21 and 82 years who were operated and met the study criteria were identified from patients with these nodules. The files of all patients were scanned and the results of age, gender, ultrasonographic nodule characteristics, FNAB repeat, type of surgery, and postoperative pathology were recorded. All data were analyzed by comparing them with nodule features. SPSS 15.0 for Windows program was used for statistical analysis.

Results:

A significant correlation was found between the incidence of malignancy and male gender and hypervascularization (p=0.017 and p=0.002, respectively). Malignancy was less in nodules larger than 2 cm (p=0.014). There was no relationship between other clinical and radiological features and malignancy. In 29 nodules with rFNAB, a significant correlation was found between malignancy and advanced age (52.9-years-old), presence of nodules smaller than 2 cm and hypervascularization (p=0.047, p=0.047, and p=0.030, respectively).

Conclusion:

We recommend careful review of patients with hypervascular, hypoechogenic, and microcalcific BC-4 nodules (male gender and older patients at greater risk). Because of the serious risk of malignancy, patients with these features should be prepared for patient management with total thyroidectomy after examination with frozen section applied to the nodule during the operation.

Overview of the Ultrasound Classification Systems in the Field of Thyroid Cytology

The increasing application of ultrasound (US) in recent years has led to a greater number of thyroid nodule diagnoses. Consequently, the number of fine needle aspirations performed to evaluate these lesions has increased. Although the majority of thyroid nodules are benign, identifying methods to define specific lesions and tailor risk of malignancy has become vital. Some of the tools employed to stratify thyroid nodule risk include clinical factors, thyroid US findings, and reporting systems for thyroid cytopathology. Establishing high concordance between US features and cytologic diagnoses might help reduce healthcare costs by diminishing unnecessary thyroid procedures and treatment. This review aims to review radiology US classification systems that influence the practice of thyroid cytology.

Less extensive surgery for low-risk papillary thyroid cancers post 2015 American Thyroid Association guidelines in an Australian tertiary centre

INTRODUCTION

The 2015 American Thyroid Association guidelines (ATA15) consider hemithyroidectomy (HT) a viable treatment option for low-risk papillary thyroid cancers (PTCs) between 1 and 4 cm. We aimed to examine the impact of ATA15 in a high-volume Australian endocrine surgery unit.

METHODS

A retrospective study of all patients undergoing thyroidectomy from January 2010 to December 2019.

INCLUSION CRITERIA

PTC histopathology, Bethesda V-VI, size 1-4 cm, and absence of clinical evidence of lymph node or distant metastases pre-operatively. Primary outcome was rate of HT before and after ATA15.

RESULTS

Of 5408 thyroidectomy patients, 339 (6.3%) met the inclusion criteria - 186 (54.9%) pre-ATA15 (2010-2015) and 153 (45.1%) post-ATA15 (2016-2019). The patient groups were similar; there were no significant differences between groups in age, sex, tumour size, proportion with Bethesda VI cytology, compressive symptoms, or thyrotoxicosis. Post-ATA15, there was a significant increase in HT rate from 5.4% to 19.6% (P = 0.0001). However, there was no corresponding increase in completion thyroidectomy (CT) rate (50.0% versus 27.6%, P = 0.2). The proportion managed with prophylactic central neck dissection (pCND) fell from 80.5% to 10.8% (P < 0.0001). Pre-ATA15, the only factor significantly associated with HT was Bethesda V. In contrast, post-ATA15, HT was more likely in patients with younger age, smaller tumours, and Bethesda V.

CONCLUSION

After the release of 2015 ATA guidelines, we observed a significant increase in HT rate and a significant decrease in pCND rate for low-risk PTCs in our specialised thyroid cancer unit. This reflects a growing clinician uptake of a more conservative approach as recommended by ATA15.

An attempt to reduce unnecessary surgical procedures... Can ultrasound characteristics help in differentiating adenoma vs carcinoma in follicular thyroid neoplasms?

INTRODUCTION AND OBJECTIVES

Thyroid nodules frequently require ultrasound and Fine Needle Aspiration Cytology (FNAC) evaluation. However, FNA cytology does not allow differentiation between follicular adenoma and carcinoma on Bethesda type IV lesions. This situation leads to many unnecessary surgical procedures because it is not possible to assure the benignity of the lesions, even when most of the specimens correspond to adenomas or even other benign lesions. The objective in this study is to establish if there are any US characteristics that would help us to predict the risk of malignancy of nodules with a pathological diagnosis of follicular neoplasm in order to achieve a more conservative management for non-suspicious nodules.

MATERIAL AND METHODS

We studied 61 nodules in 61 patients (51 women and 10 men) that underwent thyroid surgery and had histopathological results of either follicular adenoma or carcinoma. Different US characteristics of the nodules were analysed (composition, echogenicity, margin, calcification status, the presence of halo and overall observer suspicion of malignancy) and were correlated with the histopathological analysis.

RESULTS

We have found a statistically significant association between the presence of calcifications, ill-defined borders and overall observer suspicion or impression (defined by well-known suspicious for malignancy ultrasonographic features, such as calcification, poorly defined margin, and a markedly hypoechoic solid nodule; and benign ultrasonographic features, such as predominantly cystic echogenic composition and the presence of a perinodular hypoechogenic halo) with follicular carcinoma. However all those features have shown low sensitivities in the present study (30%, 30% and 50%, respectively). On the other hand, the absence of halo sign has shown a sensitivity of 100% and a negative predictive value (NPV) of 100% in our study.

CONCLUSIONS

The presence of calcifications, ill-defined borders and the overall impression or suspicion of malignancy are associated with a higher risk for follicular carcinoma in Bethesda type IV thyroid nodules but their absence does not allow to predict benignity in these nodules. Inversely, when a halo sign lesion is observed, benign follicular neoplasm should be considered.

Evaluation of the Bethesda System and the ACR TIRADS in an Endemic Goiter Region

BACKGROUND

Various factors can affect incidence of thyroid disorders and disease profiles may show abrupt changes in endemic goitrous areas. In this study, it was aimed to analyze the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) in terms of risk of malignancy and general recommendations in an endemic goiter region (EGR).

METHODS

In this retrospective study, a total of 500 patients who had thyroidectomy following thyroid fine needle aspiration biopsy were enrolled. For the assessment of thyroid cytology, BSRTC was used and for the evaluation of ultrasound features of thyroid nodules, ACR TIRADS lexicon was adopted. For the assessment of thyroid cytology, Bethesda classification was used and for the evaluation of ultrasound features of thyroid nodules, ACR TIRADS lexicon was adopted.

RESULTS

In the EGR setting, benign category of BSRTC had a cancer risk of 6.2% which was two times more than the 2017 BSRTC revision reported. Nodules 10-14.9 mm in diameter had nearly 4 times higher malignancy risk than nodules >15 mm. In this group of patients, the risk of malignancy for TIRADS level 1, 2, 3, 4 and 5 was 1.16%, 2.94%, 7%, 45.64% and 94.44%, respectively. The malignancy rates for Bethesda system category I, II, III, IV, V and VI were as follows: 14.43%, 6.2%, 19.05%, 36.73%, 75.68% and 100%.

CONCLUSIONS

There are slight differences between the common set of standards and this study results regarding risk of malignancy. This brings up the question whether there is need for revision for the use of categories and the appropriate management in endemic goiter regions.

The combination of ATA classification and FNA results can improve the diagnostic efficiency of malignant thyroid nodules

PURPOSE

To determine the diagnostic efficiency of the ATA classification and ultrasound-guided fine-needle aspiration (FNA) results in identifying the risk factors of malignancy, we analyzed the thyroid nodules of patients who underwent thyroidectomy and compared preoperative ATA classifications with FNA results.

METHODS

We retrospectively analyzed 274 nodules of 196 patients who underwent ultrasonography, FNA and thyroidectomy. Histopathological findings of thyroid nodules were considered as the Au standard in the analysis of the diagnostic efficiency of the ATA classification and FNA results. Univariate analysis and binary multivariate logistic regression analysis were applied to identify the ultrasound features associated with malignancy.

RESULTS

The overall malignancy rate of 274 nodules was 41.6%. The areas under the ROC curves (AUCs) for the ATA classification and FNA results were 0.88 and 0.878, respectively (P < 0.001). The sensitivity and specificity of the ATA classification were 86 and 86.9%, whereas those of FNA results were 68.5 and 91.4%, respectively. The specificity (98.7%) and sensitivity (94.3%) increased after the combined use of the ATA classification and FNA results. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy. Microcalcifications had the highest OR (7.58), and taller-than-wide shape had the highest specificity in BSRTC I, II, III and IV cytology.

CONCLUSION

The diagnostic efficiency of the ATA classification and FNA results in identifying malignant nodules was high, and the use of both criteria improved the diagnostic accuracy. Taller-than-wide shape, microcalcifications, hypoechogenicity and irregular margins were independent risk factors for malignancy.

Ultrasound-guided fine-needle aspiration or core needle biopsy for diagnosing follicular thyroid carcinoma?

OBJECTIVE

We evaluated the preoperative diagnostic values of ultrasound (US), fine-needle aspiration (FNA) and core needle biopsy (CNB) leading to surgery in patients with FTC.

METHODS

From October 1994 to July 2016, 298 patients with FTC who had preoperative US images and underwent US-guided FNA or CNB and surgery were included in this study. We evaluated the results of preoperative FNA or CNB based on the Bethesda system and the US findings according to the Korean thyroid imaging reporting and data system (K-TIRADS).

RESULTS

Predominant US features of FTC showed solid, hypo- or iso-echogenicity, oval smooth margin and halo with no calcification. Based on K-TIRADS, 140 (47.0%) patients with FTC were categorized as low suspicion, 133 (44.63%) as intermediate suspicion and 25 (8.4%) as high suspicion at US. Considering only FNA cytology (n = 230), 6.9% were revealed as Bethesda class I, 16.1% as class II, 37.0% as class III, 29.1% as class IV and 10.9% as class V. Considering the 68 cases with CNB results, 2.9% were revealed as class I, 4.4% as class II, 20.6% as class III and 72.1% as class IV. Despite multiple FNAs, 16.7% of the 84 patients with FTC still obtained Bethesda class I or class II. CNB results in patients with FTC had a significantly higher rate of Bethesda class IV compared to the FNA results (P < .001). FTCs with distant metastasis exhibited a significantly higher rate of Bethesda classes IV and V compared to those without distant metastasis (P = .004).

CONCLUSION

Surgery for FTC is deferred only with preoperative US and FNA. CNB in patients with FTC can lead to surgery better than FNA. Therefore, if the US feature is characteristic and a serially growing large nodule is suspected, the first attempt of CNB may be helpful in selecting a surgical candidate.

Malignancy Rate in Thyroid Nodules with Atypia or Follicular Lesion of Undetermined Significance

Introduction  Atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) is one of the six diagnostic categories of the Bethesda System for Reporting Thyroid Cytopathology. The prevalence of malignancy among Bethesda category III cytology is variable, ranging from 5% to 37% in the literature. Objective  To determine the rate of malignancy in thyroid nodules reported as Bethesda category III. Methods  A total of 495 patients underwent surgical intervention for thyroid nodules from January 2015 to December 2017. The present study included 81 cases reported as Bethesda category III, and their medical records were reviewed. Results  Out of 495 fine-needle aspiration cytology samples, 81 (16.4%) samples were labeled as AUS/FLUS. Among these 81 patients, the mean age was 43.0 years (± 13.9), with only 11 (14%) patients older than 55 years of age. Most of our patients were female ( n  = 69; 85.2%), and the rest were male. The rate of malignancy based on the final histology was of 33.3% ( n  = 27). The majority were 17 cases (21%) of papillary carcinoma, followed by follicular carcinoma ( n  = 6) (7.4%). Conclusion  The risk of malignancy can be higher than it is commonly believed, and guidelines should be based on the data from the institutions themselves for a better assessment of the outcomes.

Approaching Indeterminate Thyroid Nodules in the Absence of Molecular Markers: "The BETH-TR Score"

CONTEXT

Given the lack of easy access to molecular markers for indeterminate thyroid nodules (Bethesda (BETH) category III, IV), the clinician can either decide to get a second opinion from an expert high-volume thyroid cytopathologist, redo the FNAC after a period of 3-6 months, or send the patient for a diagnostic hemithyroidectomy. Reviewing the sonographic risk features is also one way of triaging these nodules. The ACR-TIRADS (TR) is an objective method of sonographic risk assessment and is superior to other forms of sonographic classification.

AIM

We propose combining the scoring of the TR category and BETH category (both expressed as a numerical value and summated) and look at the score which could potentially guide the clinician in deciding whom to send for surgery.

SETTINGS AND DESIGN

Observational prospective collection of consecutive patient data from the thyroid FNAC clinic.

STATISTICAL ANALYSIS USED

The BETH categories were represented numerically and summated with the TR category. The categorical outcome variables of benign and malignant nodules and the summated score was analyzed using the Kruskal-Wallis test.

RESULTS

We analyzed 450 FNAC data, out of which 403 were thyroid nodule aspirates. Out of these nodules, 96 of them underwent surgery and 64% of these nodules were malignant on final histopathology (malignant = 62 and benign = 34). The mean size of the benign nodules was 3.6 ± 2.2 cm compared to 2.8 ± 1.8 cm of the malignant nodules. After excluding those with BETH 1 (n = 4), the mean BETH-TR score for benign nodules was 6 ± 1.4 and malignant nodules 9.4 ± 2.1 (P < 0.0001). The BETH-TR score progressively increased from 7.3 ± 0.92 in follicular thyroid cancers (FTC) to 8.6 ± 1.4 in follicular variant papillary thyroid cancer (FVPTC) to 10 ± 1.3 in classic papillary thyroid cancers (PTC). Among the indeterminate nodules (BETH III and IV; n = 40), the BETH-TR score of benign nodules was 6.75 ± 1 and malignant nodules was 7.5 ± 0.72 (P value = 0.01). A BETH-TR score ≥7 gave a sensitivity of 92% specificity of 74% and correctly identified malignant nodules in 86% of cases (likelihood ratio 3.5; ROC area: 0.8841; CI 0.79-0.94).

CONCLUSION

A combined sonocytological BETH-TR score is one way to triage the management of indeterminate thyroid nodules. A BETH-TR score ≥7 gave a sensitivity of 92% specificity of 74% and correctly identified malignant nodules in 86% of cases.

The Usefulness of the Thyroid Imaging Reporting and Data System in Determining Thyroid Malignancy

OBJECTIVES/HYPOTHESIS

To determine the effect of a modified Thyroid Imaging and Reporting Data System (TIRADS) in predicting malignancy in surgically treated nodules.

STUDY DESIGN

Retrospective review.

METHODS

This study was carried out at a tertiary care center from July 2016 to July 2017. Patients were included if they had a thyroid nodule that had an ultrasound assessment with subsequent fine-needle aspiration biopsy (FNAB) as well as surgical resection. Patients were excluded if they had previous head and neck surgery. Patients were stratified into those who had a formal modified TIRADS report by the radiologist versus those who had an ultrasound report without TIRADS reporting. FNAB results were reported as per Bethesda Thyroid Cytology Criteria, and the final pathology report was nominalized as malignant or benign.

RESULTS

One hundred twenty-four consecutive patients who met the inclusion criteria listed above were included within the study. Thirty one patients (25%) had a modified TIRADS report from the radiologist, whereas 93 patients (75%) did not. There was no statistical significance between the two groups in terms of: gender (P = .24), age (P = .77), FNAB results (P = .95), final surgical pathology (P = .90), or incidental findings of malignancy (P = .09). Comparative analysis showed no statistically significant difference between the two groups in terms of the concordance of FNAB and a final pathological diagnosis of malignancy (P = .91).

CONCLUSIONS

Despite the known diagnostic utility of the TIRADS in relation to FNAB results and its widespread use, this study shows that the overall detection of malignancy is not statistically different in those who received a modified TIRADS report.

LEVEL OF EVIDENCE

3 Laryngoscope, 130: 2087-2091, 2020.

NEW PROPOSED FORMULA OF TI-RADS CLASSIFICATION BASED ON ULTRASOUND FINDINGS

Introduction

The present study aimed to introduce a new formula for classification of nodules in TI-RADS and describe ultrasonography features of benign and malignant thyroid nodules.

Methods

This study was conducted on thyroid mass in 1033 patients. The incidence of malignancy for thyroid nodules was determined by selecting malignancy coefficients. Then the patients were first classified using conventional TI-RADS classification criteria and once again according to a new proposed formula.

Results

Among ultrasonography features of thyroid nodules, the irregular shape (46.7%), unclear margin (47.3%), extension to the capsule (irregular and infiltrative margin) (85%), the marked hypo-echoic nodules (63.8%), micro-calcification (49%), and to have vertical axis (74.0%) were associated with high incidence of malignancy.

Conclusion

According to the proposed new formula for TI-RADS, there are four coefficients of 7, 3, 1 and 0 for incidence of malignancy of each one of ultrasound findings that help to standardization and unifying of TI-RADS classification. The incidence of malignancy in TI-RADS classification according to the new proposed formula was achieved as follows: group 2: 0.0%, group 3: 0.7%, groups 4a, 4b, 4c: 16.7%, 43.4%, 68.5%, and group 5: 95.2%, respectively.

ACR TI-RADS and ATA US scores are helpful for the management of thyroid nodules with indeterminate cytology

BACKGROUND

Cytologically indeterminate thyroid nodules currently present a challenge for clinical decision-making. The main aim of our study was to determine whether the classifications, American College of Radiology (ACR) TI-RADS and 2015 American Thyroid Association (ATA) guidelines, in association with The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), could be used to stratify the malignancy risk of indeterminate thyroid nodules and guide their clinical management.

METHODS

The institutional review board approved this retrospective study of a cohort of 140 thyroid nodules in 139 patients who were referred to ultrasound-guided fine-needle aspiration cytology (FNAC) from January 2012 to June 2016 with indeterminate cytological results (44 Bethesda III, 52 Bethesda IV and 44 Bethesda V) and in whom pre-FNAC thyroid US images and histological results after surgery were available. Each included nodule was classified by one radiologist blinded to the cytological and histological diagnoses according to the ACR TIRADS scores and the US patterns as recommended in the 2015 ATA guidelines. The risk of malignancy was estimated for Bethesda, TI-RADS scores, ATA US patterns and their combination.

RESULTS

Of the 140 indeterminate thyroid nodules examined, 74 (52.9%) were histologically benign. A different rate of malignancy (p < 0.001) among Bethesda III, IV and V was observed. The rate of malignancy increased according to the US suspicion categories (p < 0.001) in both US classifications (TI-RADS and ATA). Thyroid nodules classified as Bethesda III and the lowest risk US categories (very low, low and intermediate suspicion by ATA and 2, 3 and 4a by TI-RADS) displayed a sensitivity of 95.3% for both classifications and a negative predictive value of 94.3 and 94.1%, respectively. The highest risk US categories (high suspicion by ATA and 4b,4c and 5 by TI-RADS) were significantly associated with cancer (odds ratios [ORs] 14.7 and 9.8, respectively).

CONCLUSIONS

Ultrasound classifications, ACR TI-RADS and ATA guidelines, may help guide the management of indeterminate thyroid nodules, suggesting a conservative approach to nodules with low-risk US suspicion and Bethesda III, while molecular testing and surgery should be considered for nodules with high-risk US suspicion and Bethesda IV or V.

Evaluation of malignancy with thyroid imaging reporting and data system (TI-RADS) in thyroid nodules with persistent nondiagnostic cytology

Background/aim

We aimed to evaluate the utility of thyroid imaging reporting and data system (TI-RADS) in prediction of malignancy in thyroid nodules with persistent nondiagnostic (ND) cytology.

Materials and methods

A total of 246 thyroid nodules which were surgically removed and had at least two fine-needle aspirations (FNAs) with ND cytology were included in this study. Ultrasonography features and TI-RADS scores were recorded.

Results

Of 246 nodules, 218 (88.6%) had benign and 28 (11.4%) had malignant final histopathology. Frequencies of taller than wide shape, solidity, hypoechogenicity, microcalcifications, and presence of irregular borders were similar between benign and malignant nodules (P > 0.05). The number of nodules categorized as TI-RADS 3, 4a, 4b, and 4c were 12 (4.9%), 53 (21.5%), 104 (42.3%), and 77 (31.3%), respectively. There was not any nodule in TI-RADS 5 category. Malignancy rates of categories 3, 4a, 4b, and 4c were 0%, 13.2%, 9.6%, 14.3%, respectively. No significant differences were detected in TI-RADS categories between benign and malignant nodules (P > 0.05).

Conclusion

In this study, we did not demonstrate any suspicious ultrasound (US) finding predictive for malignancy in thyroid nodules with persistent ND cytology and did not determine any difference between malignant and benign nodules regarding TI-RADS scores. Whereas, we found that thyroid nodules in 4a, 4b, and 4c TI-RADS categories had higher malignancy rates than those previously reported in ND cytology. We think that TI-RADS categories in thyroid nodules with persistent ND cytology can be helpful in treatment decision.

Validation of web-based thyroid imaging reporting and data system in atypia or follicular lesion of undetermined significance thyroid nodules

BACKGROUND

Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) show variable malignancy risk. We validated the web-based predictive models and the scoring system by the American College of Radiology (ACR) for AUS/FLUS nodules to stratify the malignancy risk.

METHODS

From January 2011 to November 2014, 275 consecutive nodules diagnosed as AUS/FLUS were enrolled. The discrimination and calibration ability of a web-based scoring with inclusion of biopsy result and sonographic features, old web-based scoring model without biopsy result, and ACR models were assessed.

RESULTS

The areas under the receiver operating characteristic curve of the validation set were 0.670 for the new web-based model, 0.710 for the old web-based model, and 0.732 for the ACR scoring risk-stratification model. All models were well calibrated.

CONCLUSION

The web-based scoring risk-stratification model using the combined information of ultrasonography features and biopsy result for AUS/FLUS nodules to stratify malignancy risk presents an acceptable predictive accuracy.

TIRADS score is of limited clinical value for risk stratification of indeterminate cytological results

CONTEXT

Thyroid nodules with cytological indeterminate results represent a daily and recurrent issue for patient management.

OBJECTIVE

The primary aim of our study was to determine if TIRADS (Thyroid Imaging Reporting and Data System) could be used to stratify the malignancy risk of these nodules and to help in their clinical management. Secondary objective was to estimate if this risk stratification would change after reclassification of encapsulated non-invasive follicular variant of papillary carcinomas (FVPTC) as non-invasive follicular thyroid neoplasm (NIFTP).

PATIENTS AND METHODS

Single-center retrospective study of a cohort of 602 patients who were referred for ultrasound-guided fine-needle aspiration from January 2010 to December 2016 with an indeterminate cytological result and in whom histological results after surgery were available. TIRADS score was prospectively determined for all patients included. Nodules that had been classified as FVPTC were submitted to a rereading of histological report and reclassified as NIFTP when judged relevant. A table of malignancy risk crossing Bethesda and TIRADS results was built before and after this reclassification.

RESULTS

The study included 602 cytologically indeterminate nodules. TIRADS score was positively correlated with the malignancy rate (P < 0.0001). Risk stratification with TIRADS was significant only in Bethesda V nodules (P = 0.0004). However, the risk of malignancy in this Bethesda V category was always above 45%, whatever the TIRADS score.

CONCLUSION

For a clinician facing an indeterminate cytological result for a thyroid nodule, return to TIRADS score is of limited value in most conditions to rule in or rule out malignancy and to guide subsequent management of patients.

Diagnostic performance of ATA, BTA and TIRADS sonographic patterns in the prediction of malignancy in histologically proven thyroid nodules

INTRODUCTION

We aimed to compare the malignancy risk stratification of histologically proven thyroid nodules using the 2015 American Thyroid Association (ATA) Management Guidelines, 2014 British Thyroid Association (BTA) Guidelines for the Management of Thyroid Cancer and the Thyroid Imaging Reporting and Data System (TIRADS).

METHODS

Thyroid nodules measuring > 1 cm resected over 5.5 years were retrospectively studied. Demographic information as well as cytology and histopathology results were collected. Static ultrasonography (US) images and radiologists' reports of each resected nodules were reviewed and classified based on the above risk classification systems.

RESULTS

A total of 167 thyroid nodules from 150 patients were examined. More malignant nodules were solid (78.4% vs. 62.5%; p = 0.049) or hypoechoic (70.6% vs. 28.6%; p < 0.001), and had irregular margins (35.3% vs. 8.0%; p < 0.001), taller-than-wide morphology (9.8% vs. 2.7%; p = 0.031), microcalcifications (33.3% vs. 8.0%; p < 0.001), disrupted rim calcifications (9.8% vs. 0.9%; p = 0.012) or associated abnormal cervical lymphadenopathy (13.7% vs. 0.9%; p = 0.001) compared with benign nodules. The guidelines' diagnostic performance was: ATA - sensitivity 98.0%, specificity 17.3%, positive predictive value (PPV) 35.0%, negative predictive value (NPV) 95.0%; BTA - sensitivity 90%, specificity 50.9%, PPV 45.5%, NPV 91.8%; and TIRADS - sensitivity 94.0%, specificity 28.2%, PPV 37.3%%, NPV 91.2%.

CONCLUSION

Sonographic patterns outlined by the three guidelines displayed high sensitivity and NPV. Although isolated suspicious US features cannot predict malignancy risk, they should be considered when risk stratifying nodules that do not fit into particular sonographic patterns based on current guidelines.

Web-based thyroid imaging reporting and data system: Malignancy risk of atypia of undetermined significance or follicular lesion of undetermined significance thyroid nodules calculated by a combination of ultrasonography features and biopsy results

BACKGROUND

The purpose of this study was to construct a web-based predictive model using ultrasound characteristics and subcategorized biopsy results for thyroid nodules of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) to stratify the risk of malignancy.

METHODS

Data included 672 thyroid nodules from 656 patients from a historical cohort. We analyzed ultrasound images of thyroid nodules and biopsy results according to nuclear atypia and architectural atypia. Multivariate logistic regression analysis was performed to predict whether nodules were diagnosed as malignant or benign.

RESULTS

The ultrasound features, including spiculated margin, marked hypoechogenicity, calcifications, biopsy results, and cytologic atypia, showed significant differences between groups. A 13-point risk scoring system was developed, and the area under the curve (AUC) of the receiver operating characteristic (ROC) curve of the development and validation sets were 0.837 and 0.830, respectively (http://www.gap.kr/thyroidnodule_b3.php).

CONCLUSION

We devised a web-based predictive model using the combined information of ultrasound characteristics and biopsy results for AUS/FLUS thyroid nodules to stratify the malignant risk.

Reliability of Thyroid Imaging Reporting and Data System (TI-RADS), and ultrasonographic classification of the American Thyroid Association (ATA) in differentiating benign from malignant thyroid nodules

OBJECTIVE

Ultrasonography (US) is the best diagnostic tool for initial assessment of thyroid nodule. Recently, data reporting systems for thyroid lesions, such as the Thyroid Imaging Reporting and Data System (TI-RADS) and American Thyroid Association (ATA), which stratifies the risk for malignancy, have demonstrated good performance in differentiating malignant thyroid nodules. The purpose of this study is to determine the reliability of both data reporting systems in predicting thyroid malignancy in a tertiary care hospital.

MATERIALS AND METHODS

We evaluated 195 thyroid nodules using modified TI-RADS and ATA risk stratification. The results were compared to the cyto-pathology analysis. Histopathological results were available for 45 cases after surgery, which is considered the golden standard for diagnosis of thyroid cancer.

RESULTS

When compared with cytological results, sensitivity, specificity, negative predictive value (NPV), and accuracy were 100, 61.1, 100, and 63%, respectively, for TI-RADS; and 100, 75, 100, and 76%, respectively, for ATA. When compared with histopathological results, sensitivity, specificity, NPV, and accuracy were 90, 51.4, 94.7, and 60% respectively, for TI-RADS; and 100, 60, 100, and 68%, respectively, for ATA. All patients with malignant nodules were classified in the categories 4 or 5 of TI-RADS and in the intermediate or high suspicion risk according to the ATA system.

CONCLUSION

Both TI-RADS and the ATA guidelines have high sensitivity and NPV for the diagnosis of thyroid carcinoma. These systems are feasible for clinical application, allowing to better select patients to undergo fine-needle aspiration biopsies.

Diagnostic Utility of Molecular and Imaging Biomarkers in Cytological Indeterminate Thyroid Nodules

Indeterminate thyroid cytology (Bethesda III and IV) corresponds to follicular-patterned benign and malignant lesions, which are particularly difficult to differentiate on cytology alone. As ~25% of these nodules harbor malignancy, diagnostic hemithyroidectomy is still custom. However, advanced preoperative diagnostics are rapidly evolving.This review provides an overview of additional molecular and imaging diagnostics for indeterminate thyroid nodules in a preoperative clinical setting, including considerations regarding cost-effectiveness, availability, and feasibility of combining techniques. Addressed diagnostics include gene mutation analysis, microRNA, immunocytochemistry, ultrasonography, elastosonography, computed tomography, sestamibi scintigraphy, [18F]-2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET), and diffusion-weighted magnetic resonance imaging.The best rule-out tests for malignancy were the Afirma® gene expression classifier and FDG-PET. The most accurate rule-in test was sole BRAF mutation analysis. No diagnostic had both near-perfect sensitivity and specificity, and estimated cost-effectiveness. Molecular techniques are rapidly advancing. However, given the currently available techniques, a multimodality stepwise approach likely offers the most accurate diagnosis, sequentially applying one sensitive rule-out test and one specific rule-in test. Geographical variations in cytology (e.g., Hürthle cell neoplasms) and tumor genetics strongly influence local test performance and clinical utility. Multidisciplinary collaboration and implementation studies can aid the local decision for one or more eligible diagnostics.

Use of the ultrasound-based total malignancy score in the management of thyroid nodules

Purpose

The purpose of this study was to validate the role of the total malignancy score (TMS) in identifying thyroid nodules suspicious for malignancy through the sum of their ultrasound features.

Methods

The local ethical committee approved this prospective observational study. We examined 231 nodules in 231 consecutive patients (164 females and 67 males; age range, 20 to 87 years; median age, 59 years; interquartile range, 48 to 70 years) who underwent ultrasound followed by fine-needle aspiration cytology (FNAC). The nodules were further classified using the TMS, which considers ultrasound features (number, echogenicity, structure, halo, margins, Doppler signal, calcifications, and growth), and the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC), which considers cytological features. Patients with non-negative nodules (TBSRTC categories III to VI) underwent histological analysis, repeated FNAC, or 2 years of regular ultrasound follow-up. The associations between the final diagnosis, each of the ultrasound features, and the TMS were estimated using the chi-square test, the Mann-Whitney U test, and multivariate logistic regression. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy of the TMS.

Results

On ultrasound, 47% of the nodules (108 of 231) had a TMS <3, 18% (42 of 231) had a TMS of 3, and 35% (81 of 231) had a TMS >3. The FNAC results of 85% of the nodules (196 of 231) were benign, while 15% (35 of 231) had non-negative results. Hypoechogenicity, solid structure, the presence of microcalcifications, and the number of nodules were independent predictors of the final diagnosis, and the diagnostic accuracy of the TMS was good (area under the ROC curve, 0.82).

Conclusion

The TMS system is simple to use, reliable, easily reproducible, and closely reflects malignancy risk. Based on our results, FNAC could be limited to nodules with a TMS ≥3 without missing any cases of carcinoma.

New perspectives in the diagnosis of thyroid follicular lesions

Thyroid nodules are very common, affecting 19%-67% of the adult population. However, about 10% of them harbor a malignant lesion. Consequently, the first aim in their clinical evaluation is to exclude malignancy. Fine-needle aspiration cytology (FNAC) represents the main diagnostic tool for the evaluation of thyroid nodules. However, FNAC has a main diagnostic limit, namely cellular atypias of indeterminate significance, which require surgical excision and histological examination to differentiate benign from malignant lesions. Histology reports show that approximately 80% of these patients harbor a benign lesion. Therefore, in order to reduce unnecessary thyroidectomy, over the last years, the cytological classification of thyroid nodules has been revised and a number of new instrumental and molecular approaches have been proposed. In the present article, we will attempt to summarize the most recent cytological, molecular and echographic strategies to enhance the diagnostic accuracy of preoperative thyroid follicular lesions. In particular, we will discuss the new cytological classifications from the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), the British Thyroid Association-Royal College of Pathologists (PTA-RCPath) and the new Italian Society for Anatomic Pathology and Cytology (SIAPEC 2014. We will review molecular tests evaluated to ameliorate follicular lesion diagnosis as well as the clinical utility of the new echographic Thyroid Imaging Reporting and Data System (TI-RADS) score.

Use of the Kwak Thyroid Image Reporting and Data System (K-TIRADS) in differential diagnosis of thyroid nodules: systematic review and meta-analysis

PURPOSE

The purpose of this systematic literature review was to assess the usefulness of the Thyroid Image Reporting and Data System (K-TIRADS) classification proposed by Kwak for differentiation of thyroid nodules.

MATERIAL AND METHODS

Four literature databases were searched for relevant articles through early January 2017. A meta-analysis was performed to calculate pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-) and diagnostic odds ratio (DOR). The area under the curve (AUC) from the pooled receiver operating characteristic (ROC) was used to assess the usefulness of this classification for differentiation of thyroid nodules. Meta-analysis was conducted by using meta-analysis software.

RESULTS

We analysed six publications describing 10,926 nodules. Pooled sensitivity, specificity, LR+, LR-, DOR, and AUC for pooled ROC were 0.983 (95 % CI 0.976-0.989), 0.552 (95 % CI 0.542-0.562), 2.666 (95 % CI 1.692-4.198), 0.05 (95 % CI 0.035-0.072), 51.020 (95 % CI 15.241-170.79) and 0.938, respectively.

CONCLUSIONS

Kwak TIRADS has high sensitivity and low specificity. Thus, it is very useful to discard the benign cases and to reduce the number of biopsies.

KEY POINTS

• Routine, adequate standardization of thyroid nodules ultrasound classification is mandatory. • Kwak TIRADS parameters are accurate for differentiating focal thyroid lesions. • Kwak TIRADS system is simple to apply. • Kwak TIRADS system may become a useful diagnostic tool.

Ultrasonography-Based Classification and Reporting System for the Malignant Risk of Thyroid Nodules

OBJECTIVE

The aim of this study was to test the predictive value of a Thyroid Imaging Reporting and Data System (TI-RADS) for malignant thyroid nodules.

METHODS

Ultrasonographic data was examined for 910 thyroid nodules with histopathologically confirmed diagnoses. Nodules were placed into incomplete (category 0) or complete final categories (1, 2, 3a, 3b, 3c, 4, or 5) based on the presence and number of ultrasonographic features of malignancy, and the predictive value for the malignancy of nodules in categories 2-4 was assessed.

RESULTS

The overall rate of malignancy among thyroid nodules included in the study was 59.34%. The rate of malignancy gradually increased according to TI-RADS categories as follows: category 2, 5.4%; category 3 (a-c), 36% to 92%; and category 4, 99.0%. When nodules of category 2 were counted as benign, the reliability of the TI-RADS classification for determining the risk of malignancy was as follows; sensitivity, 98.15%; specificity, 47.84%; positive predictive value, 73.31%; negative predictive value, 94.65%; and odds ratio, 48.61.

CONCLUSIONS

The TI-RADS classification used in this study is relatively simple and provides a reliable measure of the risk of malignancy of thyroid nodules.

Cytologically indeterminate thyroid nodules: increased diagnostic performance with combination of US TI-RADS and a new scoring system

To investigate the diagnostic performance of combination of ultrasound (US) thyroid imaging reporting and data system (TI-RADS) and a new US scoring system for diagnosing thyroid nodules (TNs) with indeterminate results (Bethesda categories III, IV and V) on fine-needle aspiration (FNA) cytology. 453 patients with 453 cytologically indeterminate TNs were included in this study. Multivariate analyses were performed to construct the scoring system. The diagnostic performances of TI-RADS and the combined method were evaluated and compared. Multivariate analyses revealed that marked hypoechogenicity, taller than wide shape and absence of halo sign were independent predictors for malignancy in cytologically indeterminate TNs. Scoring system was thereafter defined as follows: risk score (RS) = 3.2 x (if marked hypoechogenicity) + 2.8 x (if taller than wide shape) + 1.3 x (if absence of halo sign). Compared with TI-RADS alone, the areas under the receiver operating characteristic curves (AUC), specificity, accuracy and positive predictive value (PPV) of the combined method increased significantly with 0.731 versus 0.569, 48.5% versus 14.1%, 76.2% versus 62.3%, and 70.9% versus 59.9%, respectively (all P < 0.05). The combination of TI-RADS and new US scoring system showed superior diagnostic performances in predicting malignant TNs with indeterminate FNA cytology results in comparison with TI-RADS alone.

Cytology-Ultrasonography Risk-Stratification Scoring System Based on Fine-Needle Aspiration Cytology and the Korean-Thyroid Imaging Reporting and Data System

BACKGROUND

The malignancy risk of a cytology diagnosis may depend on the ultrasonography (US) patterns of thyroid nodules, and management should be determined by the combined malignancy risk of fine-needle aspiration (FNA) cytology and US patterns. This study was performed to develop a clinically applicable cytology-ultrasonography (CU) scoring system for malignancy risk stratification based on FNA cytology and US patterns, according to the Korean-Thyroid Imaging Reporting and Data System (K-TIRADS).

METHODS

This retrospective Institutional Review Board-approved study included 1651 thyroid nodules (≥1 cm) with final diagnoses. The malignancy risk was assessed of the combined results of FNA cytology and the K-TIRADS for the development of the CU system. The interaction between FNA cytology and US pattern (K-TIRADS) in the malignancy risk of nodules was investigated by using a binominal test.

RESULTS

The malignancy risk of nodules could be stratified into four CU scores (very low risk, <3%; low risk, ≥3%, <30%; high risk, ≥30%, <90%; very high risk, ≥90%). In nodules with non-diagnostic, benign, and atypia of undetermined significance/follicular lesion of undetermined significance cytology results, low-suspicion US pattern (K-TIRADS 3) significantly decreased the malignancy risk of nodules (p = 0.003, 0.013, and 0.027, respectively), and a high-suspicion US pattern (K-TIRADS 5) significantly increased the malignancy risk of nodules (p ≤ 0.001). A Bethesda 1 or 4 cytology result did not significantly change the malignancy risk of any K-TIRADS (p ≥ 0.518 and p ≥ 0.137, respectively). A Bethesda 2 cytology result decreased and a Bethesda 5 or 6 cytology result increased the malignancy risk of K-TIRADS 3, 4, and 5 (p ≤ 0.001). A Bethesda 3 cytology result increased the malignancy risk of K-TIRADS 3 and 4 (p < 0.001 and p = 0.024, respectively).

CONCLUSION

The malignancy risk of thyroid nodules can be stratified by the CU risk-stratification system, based on FNA cytology and the K-TIRADS. The proposed CU scoring system may be helpful in the management of thyroid nodules after FNA.

Likelihood of malignancy in thyroid nodules according to a proposed Thyroid Imaging Reporting and Data System (TI-RADS) classification merging suspicious and benign ultrasound features

Objective

The aim of this study was to describe the ultrasound features of benign and malignant thyroid nodules and evaluate the likelihood of malignancy associated with each feature according to the Bethesda System for Reporting Thyroid Cytopathology and histopathology. With this analysis, we propose a new TI-RADS classification system.

Materials and methods

The likelihood of malignancy from ultrasound features were assessed in 1413 thyroid nodules according to the Bethesda System for Reporting Thyroid Cytopathology and histopathological findings. A score was established by attributing different weights to each ultrasound feature evaluated.

Results

Features positively associated with malignancy in bivariate analysis received a score weight of +1. We attributed a weight of +2 to features which were independently associated with malignancy in a multivariate analysis and +3 for those associated with the highest odds ratio for malignancy (> 10.0). Hence, hypoechogenicity (graded as mild, moderate or marked, according to a comparison with the overlying strap muscle), microcalcification and irregular/microlobulated margin received the highest weights in our scoring system. Features that were negatively associated with malignancy received weights of -2 or -1. In the proposed system a cutoff score of 2 (sensitivity 97.4% and specificity 51.6%) was adopted as a transition between probably benign (TI-RADS 3) and TI-RADS 4a nodules. Overall, the frequency of malignancy in thyroid nodules according to the categories was 1.0% for TI-RADS 3, 7.8% for TI-RADS 4a, 35.3% for TI-RADS 4b, and 84.7% for TI-RADS 5.

Conclusion

A newly proposed TI-RADS classification adequately assessed the likelihood of malignancy in thyroid nodules.

Thyroid Imaging Reporting and Data System Score Combined with the New Italian Classification for Thyroid Cytology Improves the Clinical Management of Indeterminate Nodules

The new Italian cytological classification (2014) of thyroid nodules replaced the TIR3 category of the old classification (2007) with two subclasses, TIR3A and TIR3B, with the aim of reducing the rate of surgery for benign diseases. Moreover, thyroid imaging reporting and data system (TI-RADS) score appears to ameliorate the stratification of the malignancy risk. We evaluated whether the new Italian classification has improved diagnostic accuracy and whether its association with TI-RADS score could improve malignancy prediction. We retrospectively analyzed 70 nodules from 70 patients classified as TIR3 according to the old Italian classification who underwent surgery for histological diagnosis. Of these, 51 were available for cytological revision according to the new Italian cytological classification. Risk of malignancy was determined for TIR3A and TIR3B, TI-RADS score, and their combination. A different rate of malignancy (p = 0.0286) between TIR3A (13.04%) and TIR3B (44.44%) was observed. Also TI-RADS score is significantly (p = 0.003) associated with malignancy. By combining cytology and TI-RADS score, patients could be divided into three groups with low (8.3%), intermediate (21.4%), and high (80%) risk of malignancy. In conclusion, the new Italian cytological classification has an improved diagnostic accuracy. Interestingly, the combination of cytology and TI-RADS score offers a better stratification of the malignancy risk.

The predictive value of sonographic images of follicular lesions - a comparison with nodules unequivocal in FNA - single centre prospective study

BACKGROUND

To determine the diagnostic efficacy of ultrasonographic malignancy risk features (UMRFs) in follicular lesions (FL) in a population with low risk of malignancy in FL and to compare it with a similar analysis in a group of patients with unequivocal cytology (UC): benign lesion (BL) or malignant neoplasm (MN).

METHODS

Presence of UMRFs (hypoechogenicity, solid echostructure, taller-than-wide shape, pathological vascularization, irregular margins, microcalcifications and macrocalcifications) and their sets were assessed in 322 FL: 202 follicular lesions of undetermined significance (FLUS) and 120 suspicious for follicular neoplasm (SFN) and 300 nodules with UC: 200 BL and 100 MN, subsequently evaluated histopathologically.

RESULTS

Cancers were confirmed in 100% nodules in MN group (89.0% of them were papillary carcinomas - PTC), in 6.4% FLUS nodules (69.2% PTC), and in 10.8% SFN nodules (30.8% PTC). In the UC group all UMRFs occurred more frequently in cancers than in benign lesions. In the FL group only calcifications were found in cancers more frequently - macro and microcalcifications together: 34.6 vs. 11.5% (p = 0.001) and isolated macrocalcifications: 26.0 vs. 6.8% (p = 0.001); the presence of those features increased the basic risk of malignancy in FL more than 2 times. The presence of at least 2 of the following URMFs: hypoechogenicity, solid echostructure, any type of calcifications and suspected shape, additionally improved sensitivity.

CONCLUSIONS

Evaluation of UMRFs in FLs is less effective than in nodules with UC, and its effectiveness decreases parallel to the decrease in percentage of PTCs among malignant neoplasms and to the increase of the percentage of adenomas among benign nodules. The presence of macrocalcifications in such FLs significantly increases the basic risk of malignancy in these nodules.

Diagnostic accuracy of ultrasound-guided fine needle aspiration biopsy for thyroid malignancy: systematic review and meta-analysis

PURPOSE

To systematically appraise and summarize the available evidence about the diagnostic accuracy of ultrasound-guided fine needle aspiration biopsy (USFNA) for thyroid malignancy, and to explore the integration of these estimates with the probability of thyroid malignancy before USFNA.

METHODS

A comprehensive search of multiple databases from each database's inception to August 2014 was performed. Eligible studies included those that evaluated patients with thyroid nodules who underwent USFNA and subsequent evaluation by histopathology or long-term follow-up.

RESULTS

We identified 32 studies at moderate risk of bias evaluating the USFNA diagnostic characteristics for the diagnosis of thyroid malignancy. Results were imprecise and inconsistent across trials. The pooled likelihood ratio (LR) of thyroid malignancy for a benign USFNA result was 0.09 (95 % CI 0.06, 0.14; I (2) = 33 %), whereas the pooled LR for a malignant result was 197 (95 % CI, 68, 569; I (2) = 77 %). In the case of a suspicious for follicular neoplasm result, the pooled LR for malignancy was 0.6 (95 % CI, 0.4, 1.0; I (2) = 84 %) and 8.3 (95 % CI, 3.6, 19.2; I (2) = 89) for a result of suspicious for malignancy.

CONCLUSION

The available evidence regarding the diagnostic accuracy of USFNA warrants only limited confidence due to risk of bias, imprecision, and inconsistency. However, some USFNA results (benign, malignant) are likely very helpful, by significantly changing the pre-test probability of thyroid cancer.

Higher TSH can be used as an additional risk factor in prediction of malignancy in euthyroid thyroid nodules evaluated by cytology based on Bethesda system

Recently, it has been suggested that thyrotropin (TSH) concentration can be used as a marker for prediction of thyroid malignancy. In this study, we aimed to investigate the association between TSH levels and prediction of malignancy in euthyroid patients with different Bethesda categories. The data of 1433 euthyroid patients with 3206 thyroid nodules who underwent thyroidectomy were screened retrospectively. The preoperative cytology results, thyroid function tests, thyroid autoantibodies, and presence of histopathological Hashimoto's thyroiditis (HT) were recorded. Of the 1433 patients, 585 (40.8 %) had malignant and 848 (59.2 %) had benign histopathology. Malignant group had smaller nodule size, elevated TSH levels, and higher rate of presence of HT compared to benign group (p < 0.001, all). Cytology results of 3206 nodules were as follows: 832 nondiagnostic (ND), 1666 benign, 392 atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 68 follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), 133 suspicious for malignancy (SM), and 115 malignant. Both SM and malignant cytology groups had higher TSH levels than other 4 Bethesda categories (p < 0.05, all). Benign cytology group had significantly lower TSH levels compared to other cytology groups (p < 0.05, all). Patients with malignant final histopathology in ND and AUS/FLUS cytology groups had significantly higher TSH levels compared to patients with benign final histopathology (p < 0.05, all). Moreover, TSH levels showed to increase from Bethesda categories II to VI. In addition to cytology, higher TSH levels can be used as a supplementary marker in prediction of malignancy in certain Bethesda categories.

Value of sonographic features in predicting malignancy in thyroid nodules diagnosed as follicular neoplasm on cytology

BACKGROUND

The cytological diagnosis of follicular neoplasm (Thy3F) remains a diagnostic challenge. The main aim of this study was to stratify the risk of malignancy in thyroid nodules diagnosed as Thy3F on cytology (Thy3F) using thyroid imaging reporting and data system (TIRADS).

METHODS

A database of thyroid nodules with Thy3F cytological results from ultrasound-guided FNA (US-FNA) between January 2007 and March 2014 was studied retrospectively. Information on patient demographics, ultrasound characteristics and final histology of the nodules was collated. The number of suspicious US features of each thyroid nodule was counted based on TIRADS. The malignancy rate of each of the TIRADS category was also calculated based on the final histological outcomes of the nodules and compared to that calculated using a recently proposed thyroid malignancy risk prediction model.

RESULTS

The overall malignancy rate of Thy3F cytology was 24·3%. There were significantly higher percentages of malignant nodules with irregular margins (20·0% vs 0%, P = 0·000), hypo-echogenicity (74·3% vs 51·4%, P = 0·013) and taller-than-wide morphology (17·1% vs 0·9%, P = 0·001) when compared to benign nodules. The risk of malignancy increased with advancing TIRADS score: TIRADS 4A (14·3%), TIRADS 4B (23·1%), TIRADS 4C (87·5%) and TIRADS 5 (100%). The malignancy rate calculated using the prediction model similarly increased with advancing TIRADS score: TIRADS 4A (6·2%), TIRADS 4B (32·5%), TIRADS 4C (79·9%) and TIRADS 5 (90%).

CONCLUSION

Thyroid nodules with TIRADS scores 4C and 5 should be considered for single definitive surgery in view of the high malignant rate.

Outcome of thyroid gene expression classifier testing in clinical practice

OBJECTIVES/HYPOTHESIS

Gene expression classifiers can safely reduce diagnostic thyroid surgery for fine-needle aspiration cytology (FNAC) indeterminate thyroid nodules.

STUDY DESIGN

Retrospective review, single-institution, single-practice surgeon.

METHODS

Three-year retrospective review of indeterminate FNAC that went on to gene expression classifier testing.

RESULTS

A total of 520 patients met American Thyroid Association guideline criteria for surgeon-performed ultrasound-guided FNAC for a thyroid nodule with on-site cytopathology. The indeterminate (Bethesda III or IV) FNAC rate was 9%. Prevalence of malignancy in FNAC indeterminate was 21%. Thirty-two cases went on to gene expression classifier testing. Fourteen were benign, 15 suspicious, and three with no result.

CONCLUSIONS

Benign gene expression classifier testing had an estimated negative predictive value of 100% during the study period. These patients have been observed for a mean and median duration of 14 and 7 months, respectively. In this small series, 14 of 29 patients with indeterminate FNAC were spared diagnostic surgery.

LEVEL OF EVIDENCE

4.